1. Field of the Invention
The invention relates to an apparatus for containing transmission line connectors, and more specifically, to an expandable surface mount box for transmission line connectors.
2. Technical Backgrounds
High quality transmission lines have been provided for electrically connecting various electronic components to improve data transmission rates. A transmission line can be more adaptable if it is connected to the electronic components through connectors. The connectors include a first-type connector and a second-type connector. The transmission lines are connected to the electronic components by engaging the second-type connector with the first-type connector. That is, an electrical loop can be formed if the second-type connector is inserted into and received by the first-type connector.
FIG. 1 is a perspective view of a conventional two-port containing box 10 for transmission line connectors. The box is composed of a cover 12 and a substrate 14. Two ports 121 and 123 in a front end of the box are provided for holding two first-type connectors. Two windows 125 and 127 are formed, near the front end of the box, on the top surface of cover 12 for inserting cards which are provided for indicating various connector ports of the box.
A more detailed view of substrate 14 is illustrated in FIG. 2 whose horizontal direction has a 90.degree. rotation from that shown in FIG. 1. Therefore, the opposite side of the front end, i.e., a rear end of the box, can be shown in the figure. Substrate 14 includes a plate and a number of short walls standing near edges of the plate. The short walls are provided for fastening side plates of the cover 12 when the cover 12 is engaged with the substrate 14. Two spaced posts 141 and 143 stand at edge center of the rear end of the plate to define a passage for a transmission line 147. A small cut 145a is formed at the plate edge between the two posts 141 and 143 to facilitate entering of transmission line 147 into the box.
However, the passage between posts 141 and 143 is not the only path by which transmission lines can go into the box. For example, the transmission line can go through the spacing between each post and its adjacent short wall. Therefore, when cover 12 is engaged with substrate 14 and the transmission lines do not go through the passage defined between the two posts, as is shown in FIG. 3, transmission lines 148 and 149 are pressed by rear-end side plate of cover 12 and substrate 14. The transmission lines crushed by side plate of cover 12 will be damaged, thus causing an open circuit in the transmission line.
Moreover, the conventional containing box cannot be expanded. That is, the box is provided with a fixed number of ports. For example, if an additional transmission line is introduced into a two-port box which has already been installed with two connectors for two transmission lines, the two-port box cannot accommodate the expansion. Therefore, a four-port box must be substituted for the two-port box which must then be subsequently discard.